CVE-2026-42945

NGINX has released updates (versions 1.30.6 and 1.31.7) to address five vulnerabilities, including potential remote code execution (RCE) and a TLS session forgery flaw that could bypass client-certificate checks. The most severe flaws are heap overflows and a use-after-free condition, exploitable under specific configurations involving alias with rewrite, regex maps, AIO with SSI, or shared TLS session caches. The TLS flaw (CVE-2026-97629) stems from improper rotation of session ticket keys, allowing non-deterministic forged session resumption. No active exploitation has been reported, but prior NGINX flaws have seen rapid weaponization post-disclosure.

Multiple active threats were reported this week, including Russian threat actors exploiting a Microsoft OWA XSS vulnerability (CVE-2026-42897) to deploy a JavaScript-based implant called OWAReaper for persistent mailbox access. A critical Ruby on Rails vulnerability (CVE-2026-66066) allows unauthenticated attackers to read arbitrary files via crafted image uploads, potentially leading to remote code execution. Additionally, Iranian-linked actors are suspected in coordinated attacks on over 30 Minnesota water systems, where exposed PLCs were targeted to disrupt operations. Storm-2945 (APT29) conducted DNS hijacking via compromised Wi-Fi networks to deliver CornFlake malware and ChocoShell infostealer, while a malicious campaign in RubyGems distributed 199 trojanized packages embedding XMRig cryptojacking payloads.

A critical vulnerability in NGINX, tracked as CVE-2026-42533, allows remote unauthenticated attackers to trigger a heap buffer overflow via crafted HTTP requests, potentially leading to denial of service or remote code execution. The flaw exists in NGINX's script engine under specific configurations involving regex-based maps and capture overwrites. Exploitation may bypass ASLR, increasing the risk even on default systems, though no public exploits have been observed yet. F5 has released patches for core NGINX and NGINX Plus, but downstream products lack updated builds at the time of publication.